
#include<iostream>
#include<algorithm>
#include<vector>
using namespace std;

int maximalSquare(vector<vector<char>>& matrix) {


    if (matrix.size() == 0 || matrix[0].size() == 0) {
        return 0;
    }
    int maxSide = 0;
    int rows = matrix.size(), columns = matrix[0].size();
    vector<vector<int>> dp(rows, vector<int>(columns));
    for (int i = 0; i < rows; i++) {
        for (int j = 0; j < columns; j++) {
            if (matrix[i][j] == '1') {
                if (i == 0 || j == 0) {
                    dp[i][j] = 1;
                }
                else {
                    dp[i][j] = min(min(dp[i - 1][j], dp[i][j - 1]), dp[i - 1][j - 1]) + 1;
                }
                maxSide = max(maxSide, dp[i][j]);
            }
        }
    }
    int maxSquare = maxSide * maxSide;
    return maxSquare;



}
